graph TD
    Root[项目结构] --> A[源代码]
    Root --> B[文档]
    Root --> C[测试]
    Root --> D[配置]

    A --> A1[组件]
    A --> A2[服务]
    A --> A3[工具]

    B --> B1[API文档]
    B --> B2[使用说明]
    B --> B3[示例]

    C --> C1[单元测试]
    C --> C2[集成测试]
    C --> C3[性能测试]

    D --> D1[环境配置]
    D --> D2[构建配置]
    D --> D3[部署配置]

    classDef default fill:#f9f,stroke:#333,stroke-width:1px;
    classDef root fill:#f96,stroke:#333,stroke-width:2px;
    classDef category fill:#bbf,stroke:#333,stroke-width:1px;

    class Root root;
    class A,B,C,D category;
